When we speak about network blocking, we tend to think about “filtering” users’ ability to use and/or access the Internet. As a result, these actions create technical complexities that affect users who access different services in content networks. It is common to observe restrictions on the use of and/or access to the Internet, implemented either by blocking certain websites or domain names or by limiting the use of content, all of which causes a fragmentation of the Internet. In any case, it should be noted that the consequences of such actions may typically go unnoticed by clients and/or users both within and outside the region. These implications might range from the involuntary and intermittent disconnection of a third-party website to completely disabling the networks of operators in a given area or even in an entire country. When website blocking becomes the natural alternative used to limit undesired behaviors, one should be aware of the implications of such measures. Unintended Consequences of Website Blocking IP Addresses and ASNs for Research Purposes.RIPE Atlas in Latin America and the Caribbean.Incident Response Center - LACNIC CSIRT.